team used to arrest dzhokhar tsarnaev. they did not know if he would pull out a weapon or explosive device. they described to anderson cooper how they subdued him. >> we got close enough that at one point where both of his hands were up because of the rocking back and forth, both of his hands were up, we could see that there were no weapons in them, no ignition devices we broke away from the shield protective cover. and we just rushed him. put hands on him, grabbed him and pulled him off the boat down onto the grounds. >> all right the reason the s.w.a.t. team immediately pulled off his shirt was to check if he was wearing explosives inside a suicide vest, perhaps. let's bring in jim walsh, cnn's international security analyst. we heard from jake tapper. his reporting indicated that investigators are now communicating with dzhokhar tsarnaev, the 19-year-old suspect in the boston marathon bombing attack and learning from him, at least initially, he says that they were radicalized by watching videos online. no direct communi